Automatic switch as used in telephone or like systems



v 1940- D. WRIGHT I 2,186,313

AUTOMATIC SWITCH AS USED IN TELEPHONE OR LIKE SYSTEMS Filed March 19, 1938 INVEN TOR DEN/5 WR/GH T ATTY Patented Jan. 9, 1940 .-2",1ss,ij3, AUTQMATTC SWITCH. AsirisEni Is-3'; 'rELE,- i a PR,P 'S MS ,4 Denis Wright, "Liverpool,: tEnglandg assignor to Associated Telephone Telegraph ,Company', 2 I cago, ll a cor o ti n,.ofp a re Application Maren-r9. lsss'yser'ie'l" InGreat Britain-March cog- 1937 "1 The present invention relates switches as used in telephone or likesystems 'and is more particularly concerned With-3111011111?- ing arrangements fcr switches of, the two-di rectional type arrangedto have longitudinal and rotary motion. h g In such switches as ,iswell known-the-controlling relays, driving mechanism andyripers- I .of each switch are nerally provided; as ,a single off-normal position;

unitwhich is readily detachable fromthe. sup.- port. (commonly referred toasa switch fshelf) upon which it is mounted. The multiply-cone nected' contact banks are fixed to the shelfin such a position as to beaccessible to'the wipers of their respective switches' when the switches are mounted, and thereis accordingly the danger that when such switches'fare replaced in posif tion. the wipers will become damaged by engageprovide an improved guarding device suitable for attachment to switches of the above type which will prevent their reengagement with the bank if their wipers are in an off-normal position.

According to the invention a movable member adapted to co-operate with the switch wipers is so arranged as to ofier resistance to the mounting of the switch on its support if the wipers are in such a position that they would be likely to suffer damage by such action.

The invention will be better understood from the following description of one method of carrying it into effect reference being had to the accompanying drawing comprising Figs". 1 and 2, which show the guarding device applied to the two-directional switch and mounting arrangement disclosed inv the Saxby patent previously referred to. Fig. 1 is a front perspective view of the lower portion of the switch and bank as it appears when the switch is mounted upon the v shelf as described in the Saxby patent. The wipers are shown in their normal position slightly below and to the left of the contact bank; in

to automatic safety iii-g only 'sufii'ci'ent of the constructional details -of tl ie' 'sv'v'itch have been shown as are necessary for describingthe applicationbf the invention;

. V c oieim fi (011 051663 this position the wiper carriage is prepared to engage one arm of the pivoted safety catch l3 whenthe switch is-liftedfrom its mounting. Fig.

""view of the switch when removed h "shelf, and shows the wipers in an'o'ff orr lposition 'topermit rotation of the catch! As will be seen from the draw- Referring-now to Fig. 1 the vertical slots in-the siderneinbers Hland H engage lugs on opposite sides of. the inountingbracket member l2, which is similar to thebracket member [4' shown bolted tofthe-"lower" Contact bank in the above-mentioned patent tdSaxby, while (the pivoted safety 'fc'at'ch it; which is] added in (accordance with thef inv'ention',ibears' against the inclined face *Mof thebr'acket and'isthus held slightly clear of the lower wiperiassembly Hi; This is the normal position of the safety catch and so long as this positionis maintained, as it must be when the switch is correctly mounted, there can be no interference, with the operating and releasing movements of the wiper assembly.

When the switch is removed from its mounted position with the wipers still in their normal position, the pivoted safety catch 13 loses the support of the inclined face l4 of the" bracket l2 and is then urged by the hairpin spring I6 against the fibreportion of the lower wiper assembly IS. The movement of the safety catch in these circumstances is however very slight, since it is only required to take up the clearance betweenitself and the wiper assembly and to all intents and purposes the safety catch may be regarded as having been maintained in its normal position.

If however the wiper carriage is moved by hand from its normal position with the switch removed from its mounting, the-fibre portion of the lower wiper assembly is raised clear of the safety catch, which swings to the left under the influence of the hairpin spring until it comes vup against the side member ill in which position the tapered end of the catch blocks the opening to the vertical slot in the sidemember 10; This is the condition illustrated in Fig. 2..

Accordingly'if thewiper carriage is left in'an oiT-normal position and an attempt is made to replace the switch in its mounted position on the bracket, the end of the safety catch will foul the lug on the bank contactwhich would otherwise enter the vertical slot in the side member Ill, with the result that the attempted replace- 5;

ment of the switch is prevented and attention is called to the off-normal condition of the wipers.

the fibre part of the lower wiper assembly comes up against the safety catch which it swings to the right in order to open the slot in the side member ID. The mechanism is now in the'correct condition for the replacement of the switch on the supporting bracket, and when this is done, the safety catch rides along the inclined face M of the bank bracket and is thus caused.

to execute a further slight 'movement to. the right in order to produce a clearance between itself and the wiper assembly as is desirable during normal operation.

I claim:

1. In combination, a support, a bank of contacts in fixed relationship to said support, a switch having movable wipers, means for detachably mounting said switch upon said support thereby to place said wipers in operative relationship with said bank of contacts, and means controlled by the position of the wipers to prevent the mounting of said switch upon said support if said wipers are in such a position as to be damaged by said contacts in the mounting of the switch.

2. In a combination as claimed in claim 1, wherein said last means includes a member at times mechanically linked tosaid wipers when said switch is detached from said support,means controlling said member to prevent the same from being linked to the wipers when said switch is mounted upon said support.

3. A combination as claimed in claim 1, where in said switch is a two-motion switch whose wipers have a longitudinal movement and a rotary movement.

4. In combination, a support, a bank of contacts in fixed relationship to said support, a switch having movable wipers, means for detachably .mounting said switch upon said support thereby to place said wipers in operative relationship with said bank of contacts, said wipers having a normal position, and means for preventing the mounting of saidswitch upon said support if said wipers are not in said normal position.

5. In a mounting arrangement, a support, a switch, means including 2. lug and slot combination for detachably mounting said switch upon the support, a member at times blocking said slot when said switch is detached from said support thereby to prevent said switch from being mounted upon said support, movable wipers carried by said switch, and means controlled by the position of said wipers for at other times preventing said member from blocking said slot.

6. In a mounting arrangement, a support, a bank of contacts in fixed relationship to said support, a switch having movable wipers, means including a lug and slot combination for detachably mounting said switch upon the support thereby to place said wipers in operative relationship with said bank of contacts, a member controlled in accordance with the position of said wipers when said switch is detached from said support, and means for operating said member to block said slot if said wipers are in such a position as to be damaged by the bank of contacts in the mounting of said switch.

DENIS WRIGHT. 

